Machine for playing disk-type phonograph records



March 26, 1957 SCHWEITZER 2,786,685

MACHINE FOR PLAYING DISK-TYPE FHONOGRAPH RECORDS Filed Jan. 22, 1953 2 Sheets-Sheet 1 Z, WTOR.

March 26, 1957 E. SCHWEITZER 2,786,685

MACHINE FOR PLAYING DISKQTYPE PHONOGRAPH RECORDS Filed Jan. 22, 1953 2 Sheets-Sheet 2 7 1 -wf. MM/

4 58 5.9 Z 9 INVENTOR.

United States Patent MACHINE FOR PLAYING DISK-TYPE PHONOGRAPH RECORDS Erich Schweitzer, Kenmore, N. Y., assignor to Markel Electric Products, Inc., Buffalo, N. Y., a corporation of New York Application January 22, 1953., Serial No. 332,730

7 Claims. (Cl. 274-15) This invention relates to a machine for playing disktype phonograph records and more particularly to a mechanism operative to move the tone arm horizontally to operative and inoperative positions with reference to the record playing zone.

One of the important objects of the present invention is to provide such a mechanism for moving the tone arm horizontally to operative and inoperative positions which is of simple and rugged construction and will operate under conditions of severe and constant use without getting out of order or requiring adjustment or repairs.

Another object is to provide such a mechanism which is precise in its operation, particularly in conjunction with the indexing and set down and lifting mechanisms forming the subject of said companion applications.

Another object is to provide such a mechanism for effecting horizontal movement of the tone arm which operates with little power, thereby to contribute a minimumv amount to the load on the motor which is also used to rotate the records and to operate other mechanisms.

'.Another object is to provide such a mechanism which is free from the necessity for extremely close tolerances andfits.

Another aim is to provide such a mechanism which does not contribute to undesired sound effects either directly, as through rattling or vibrating, or indirectly, as through inducing wows or rumbles in the playing of arecord.

,Another 'aim is to provide such a mechanism which can be used in the selective or automatic playing of difter-ent sized records, such as the seven, ten and twelve inch disk records now in common use.

Another purpose is to provide such a mechanism which is adapted for use, without alteration, in a record .ch'a-nger adapted to play the upper sides only of records or to a record changer of the type shown in the Lynch Patent 2,555,895 dated June 5, 1951 in which each record can be played from both of its faces.

Another aim is to provide such a mechanism in which at any time the tone arm can be seized and manually turned in a horizontal direction without injury or breakage ofanyparts of the mechanism.

, .Otherobjects and advantages of the present invention will .be apparent from the following description and drawingsin which:

Fig. .l is a diminutive top plan view of a machine for playing disk type records and having a mechanism embodying the present invention for efiFecting horizontal movement of the tone arm.

Fig. '2 is an enlarged view similar to Fig. 1 with the turntable removed and with other parts broken away and insection better to disclose the mechanism.

Fig. 3' is a further enlarged .tragnientary vertical sec-. tion taken generally on line 3-3, Fig.2.

'Fig. 4 is a fragmentary vertical section taken generally .on line 44, Fig. 12.

Fig. .5 is an enlarged section taken on line .575, Fig. 2.

Figs. 69 are schematic views similar to Fig. 2 and showing successive positions of the parts following the normal record playing position illustrated in Fig. 2.

2,786,685 Patented Mar, 26., 1957 The operating parts of the record changer having the mechanism embodying the present invention are shown as mounted on a sheet metal base plate 10 which is generally square in plan and has a downturned marginal rim 11 and a central circular opening 12 over which the turntable 13 is arranged.

A horizontal metal subplate 15 is arranged below the base plate 310 in spaced relation thereto and is fixed to this base plate in register with the opening 12. For this purpose three brackets 16 are arranged in spaced radial relation around the opening 12, each having an Upper horizontal end extension 17 secured by screws 18 to the underside of the base plate 10 and each having a lower horizontal opposite end extension 19 secured by bolts 26 to the upper side of the subplate 15, a tubular spacer 21 surrounding each of the bolts 20 and being interposed between the base plate and subplate.

The subplate 15 carries a stationary center post 22 which extends coaxially through the rotatable turntable l3 and on which the records 23 to be played are threaded to rest on and be rotated by the turntable. A ten-inch record 23 is shown in full lines, the rims of twelve and seven-inch records being shown by dot-dash and dotted lines, respectively. The base plate 10 also carries groups 24 and 25 of control knobs and buttons the former also preferably providing a post for the usual stabilizer arm (not shown) leading to the center post 22.

On one side of the base plate 10 is mounted the tone arm 28. The free end of this tone arm is shown as having at its free end an upwardly projecting stylu 29 and a downwardly projecting stylus 30 one of which tracks the playing groove of the record being played. The tone arm is pivotally supported at its other end on a vertical tubular support 31 fixed to and extending through the base plate 10 as best shown in Fig. 3. The tone arm is moved horizontally by a vertical tubular shaft 32 which is journalled in the support 31 and operatively connected at its upper end to the tone arm 28 so that the tone a1 'm swings horizontally in unison with' the tubular shaft 32. Vertical movement of the tone arm can beeflected by reciprocating rod 33 extending through the tubular shaft 32. Y

The subplate 15 carries a continuously rotating pinion 35 which is concentric with the center post and which can also support and rotate the turntable 23. This continuously rotating pinion is arranged to mesh with a mutilated gear wheel 36 which is also journalled on the subplate 15. The mutilated or toothless position of this mutilated gear 36 is indicated at 38.' At the start of a record changing cycle the toothless part 38 of the mutilated gear 36 is in register with the continuously rotating pinion 3S and hence the mutilated gear 36 remains stationary. Tostart the record change cycle, the mutilated gear 36 is rendered operative to engage its teeth with the continuously rotating pinion so that the mutilated gear 36 is driven one complete revolution and stops when the continuously driven pinion 35 reenters the toothless position 38. During this one complete revolution of the mutilated gear 36, the record changing cycle is completed and the tone arm 28 must be swung horizontally outward from the center of the played record 23 to the position shown in Fig. l where it is outside the record zone. Thereafter it must 'be moved back again ffar enough to register with the starting groove of the record 23 to be played. The present invention is directed to a mechanism for effecting such horizontal movement of the tone arm 28.

The numerals 40 and 41 represent a pair of horizontal cam arms made .of flat sheet metal and arranged superimposed and in .face-to-face relation above each other and both arranged above the mutilated gear 36. V a i The cam arm 4'0"rests upon the cam lever 41 and at one end is' pivoted on a stationary upstanding pivot pin 42 at the upper end of a supporting post 43 which is secured to the upper face of the subplate 15 and also forms a shoulder for supporting the corresponding ends of the cam 40 and 41. The cam arm 41 is also secured to this upstanding pivot pin 42 of the post 43 through a 'slot 44 extending longitudinally of the cam arm 41 so that the cam arm 41 is capable of longitudinal movement with reference to the pivot pin 42 and cam lever 49 and supporting post 43. The opposite end of the cam arm 41 is provided with an upstanding straight portion 45 which is arranged tangential to a collar 46 secured by a set screw 48 to the tubular shaft 32 with which the tone arm 28 moves in unison. A ball bearing 49 can be interposed between this collar 46 and the lower end of the stationary support 31 for the tone arm and the upstanding part 45' of the cam lever 41 is faced with a rubber band t? adapted to frictionally engage the periphery of the collar 46.

The cam arms 40 and 41 are also supported on the enlarged upper end 51'of a supporting post 52, this supporting post having an upstanding pin 53. This pivot pin 53 extends through a longitudinal slot 54 in the cam lever 41 and through a transverse slot 55 in the cam lever 40. Accordingly the cam arm 41 can move longitudinally with reference to the stationary pin 53 (as it can also with reference to the stationary pivot pin 42) and the cam arm 40 can move transversely with reference to the stationary pin 53 (but can only pivot around the axis of the stationary pivot pin 42). It will particularly be noted that the longitudinal slot 54 is of substantially greater width than its pin 53, this excess width providing clearance to permit the cam arm 41 to swing about the pivot pin 42 such an extent as, to make and break frictional contact between the friction facing 50 and the collar 46. The transverse slot 55 is also preferably wider than the pin 53 to insure clearance while the cam arm 49 swings about the pivot pin 42.

v The end of the cam arm 44) adjacent the tubular shaft 32 which swings the tone arm is provided on opposite sides with depending lips 56 and 57. These lips engage the opposite sides of the cam arm 43.. The cam arm 40 is also provided with an car 58 to which a helical tension spring 59 is secured. This spring is horizontally disposed and is anchored on a stationary pin 60 depending from the base plate and disposed so as to bias the friction facing 51) into engagement with the collar 46.

The cam arms 40 and 41 are horizontally offset at their centers away from each other, as indicated at 61 and 62, respectively, to provide jointly an internal earn track or opening 63. An upstanding pin 64 on the mutilated gear 36 is disposed in this opening and rides along this cam track to control the movement of the cam arms 46 and 41.

The cam track of the cam arm 4% is provided with a single salient at having a recessed land b at its peak. The cam track of the cam arm 41 is provided in succession with a salient c, a receding portion or dwell d, a salient e and a receding portion or dwell 7. The path of the pin 64 is indicated by dotted circles g and the mutilated gear rotates counterclockwise as viewed in Figs. 2 and 69.

Operation position of the tone arm' This position of the parts is illustrated in Pig. 2 and it will particularly be noted that the pin 64 is in the recessed land b at the peak of the salient a of the cam lever 49. It will also he noted that at this time the continuously rotating pinion 35 is in the 4 mutilated or toothless portion 38 of the mutilated gear 36' so that this mutilated gear 'is stationary.

When either stylus 29 or 30 reaches the inner end of the groove of the record 23 being played, a trip mechanism (not shown) is actuated. to advance the mutilated gear 36 a few degrees counterclockwise as viewed in Figs. 2 and 6-9. This causes the teeth. of this mutilated gear 36 to engage the teeth of the continuously rotating pinion 35 so that the mutilated gear is rotated one complete revolution, counterclockwise as viewed in Figs. 2 and 69, when the continuously rotating pinion again reaches the toothless portion 38 and the drive to the mutilated gear 36 is broken. The mechanism of the present invcntion is carried through a complete cycle of operation during this single rotation of the mutilated gear 36.

At the start of this cycle of operation a mechanism (not shown) moves the tone am 28 vertically away from the surface of. the record 23 being played. This surface can be either the upper surface played by the stylus 30 or the under surface played by the stylus 29. The mechanism of the present invention which moves the tone arm horizontally out of the record zone to permit dropping of a record and then moves the tone arm horizontally into the starting groove of the next record surface to be played, then goes into action.

Thus as the mutilated gear 36 starts its counterclockwise rotation from the position shown in Fig. 2, the first effect is to move the pin 64 out of the recessed land b on the salient a and away from this salient. This position of the parts is illustrated in Fig. 6 and it will be noted that when the pin 64 is so out of engagement with the salient a the friction facing 50 is drawn radially into frictional engagement with the collar 46 fast to the vertical tubular shaft 32 which turns in unison with the tone arm 23 so as to control its horizontal position. This frictional or driving engagement is established by the spring 59 which draws the cam arm clockwise about its pivot pin 42, as viewed in Figs. 2 and 6-9 and,

I through the car 56, similarly draws the cam arm 41 clockwise about this pivot pin. It will be noted that the longitudinal slot 54 is of greater width than the stationary pin 53 to permit such external movement of the cam arm 41 under the influence of the spring 59.

With this frictional or driving connection established between the friction facing 50 at the end of the cam arm 41 and the collar 46, which controls the horizontal position of the tone arm 28, it will be seen that moving the cam arm 41 longitudinally will swing the tone arm about its horizontal axis. it will further be seen that the longitudinal slots 44 and 54 permit such longitudinal movement of the cam arm 41 with reference to the fixed pins 42 and 53.

As the pin 64 on the mutilated gear 36 continues its counterclockwise rotation from the position shown in Fig. 6 it encounters the salient c of the cam arm 41. The rotary movement of the pin 64 is therefore translated into a longitudinal movement of the cam arm 41 to the left as viewed in Figs. 2 and 6-9. In this movement the cam arm 41 is guided by the fixed pins 42 and 53 which travel along the slots 44 and 54 of the cam arm 41 so that the cam arm 41 and its friction facing 50 are moved tangentially with reference to the collar 46. This lon; gitudinal movement of the cam arm 41 is in turn translated through the friction facing 50 into a rotary movement of the collar 46, vertical tubular tone arm shaft 32 and tone arm 28 in that direction which brings the tone arm to a position outside of the record zone.

While the pin 64 on the mutilated gear 36 is traversing the dwell d following the salient c, a mechanism. (not shown) lowers a record to position a fresh face for'play by one or the other of the styluses 29 or 30.

Following this the pin 64 on the mutilated gear wheel 36 encounters the salient e on the cam arm 41. Through this salient the movement of the pin 64 is. translated into a movement of the cam arm 41 to the right as viewed Figs. 2 and 6-9, the cam arm again being guided through its longitudinal slots 44 and 54 on the stationary pins 42 and 53. i This movement of the cam arms 41 is trans lated through its friction facing 50 into a rotary movement of the collar 46, vertical shaft 32 and tone arm 28 in that direction to swing the free end of the tone arm toward the center of the record 23 to be played.

This return movement of the tone arm 23 is stopped by an indexing mechanism (not shown) which stops the tone arm 28 .in a position in which its sty us 29 or 36? is arranged directly below or above, respectively, the starting groove of the seven, ten or twelve inch record to be played. During the movement of the pin 64 along the dwell 7 following the salient e, a mechanism (not shown) moves the tone .arm 23 vertically to effect engagement between the cooperating stylus and starting groove.

The pin 64 :on the mutilated gear 56 then engages the salient a of the cam arm 46 to move this cam lever counterclockwise as viewed in Figs. 2 and 6-9. This movement of this cam arm about its pivot pin 42 is permitted by its transverse slot 55 in which the other stationary pin 53 travels. This swings the friction facing 50 out of engagement with the collar 46. This is cffected by counterclockwise movement of the cam arm 40 about the pivot pin 42 and transmitted through its car 57 to the cam arm 41 which carries the friction facing 50. Such movement of these arms is permitted by the excessive width of the guide slot 54 in .the cam lever 41.

When the pin 64 enters the recessed land b of the salient a the continuously rotating pinion 35 encounters the toothless portion 38 of the mutilated gear 36. Accordingly rotation of this mutilate-d gear stops and the mechanism is restored to the condition assumed at the start of this description of the operation. Accordingly the mechanism is in condition for another cycle of operation.

it will be seen that the friction facing 50 could be on the periphery of the collar 46 instead of the cam arm 41 and that essentially the invention comprises the arm 41 having a face, such .as the face of the upward extension 45, arranged generally tangentially to the peripheral face of the collar 46, a friction facing on one of these faces, means such as the stationary pins 42, 53 and the slots 44, 54, movably mounting this arm on the base plate for movement of the said face both tangentially and radially with reference to the peripheral face of the collar 46, and means, such as the mutilated gear 36, its pin 64, the other cam arm 4t} with its fingers 56 and 57 together with the spring 59, for sequentially moving said first arm 41, first, to move its said face radially toward said collar 46 to effect engagement between the friction facing 50 and its companion face or the periphery of the collar 46, second, to move said friction facing 50 and its companion face or the periphery of the collar 46 tangentially with reference to each other in one direction, third, to move said friction facing 50 and its companion face on the periphery of the collar 46 tangentially with reference to each other in the opposite direction, and fourth, to move the said face of the first arm 41 radially away from said collar 46 to break contact between said friction facing 50 and its companion face or the periphery of the collar 46.

I claim:

1. In a machine for playing disk type phonograph records having a base plate, a tone arm rotatably mounted on said base plate for movement in a generally horizontal direction into and out of the record playing zone, and a collar rotatable in unison with said tone anm in such movement and having a peripheral face, the combination therewith of a mechanism for moving said tone arm horizontally into and out of said record playing zone, comprising a pair of flat aims arranged in face-toface relation with each other in planes generally at right angles to the axis of said collar, one of said arms having a face arranged generally tangential to said peripheral face, a friction facing on one of said faces, means movably mounting said one of said arms on said base plate for both reciprocating and oscillating movement to move its said face both tangentially and radially with reference to said collar, a pair of oppositely protruding salients on said one of said arms one projecting in a direction generally toward said collar and the other projecting in a direction generally away from said collar, a third salient on said other of said arms and projecting in a direction generally perpendicular to said pair of salients, cam means rotatably mounted on said base plate for rotation about an axis generally parallel with the axis of said collar and progressively engaging said salients, and means transmitting movement of said other of said arms in the di rection of projection of said third salient to said one of said arms whereby said cam means sequentially swings said one of said arms first to move its said face radially toward said collar to effect engagement between said friction facing and its companion face, second reciprocates said one of said arms to move said friction facing and its companion face tangentially with reference to each other in one direction, third reciprocates said one of said arms to move said friction facing and its companion face tangentially with reference to each other in the opposite direction, and fourth swings said one of said arms to move said face of said arm radially away from said collar to break contact between said friction facing and its companion face.

2. A structure as set forth in claim 1 wherein said movement transmitting means comprises a finger on either of said arms and arranged alongside the companion arm.

3. A structure as set forth in claim 1 wherein said movement transmitting means comprise fingers severally projecting from either of said arms alongside the companion arm. 1

4. A structure as set forth in claim 3 wherein a spring anchored on said base is connected with said other of said arms and through one of said fingers biases said face toward each other.

5. A structure as set forth in claim 1 wherein said one of said arms is elongated and arranged generally tangentially to said collar with its said face arranged at one end thereof, and wherein said means for movably mounting said one of said arms .on said base includes a stationary pin projecting through a longitudinal slot at the end of said one of said arms remote from its said face, and through a pivot hole provided in the corresponding end of said other of said arms.

6. A structure as set forth in claim 5 wherein said means for movably mounting said one of said arms on said base plate additionally includes a second stationary pin proecting through a longitudinal slot in said one of said arms and arranged intermediate said face of said one of said arms and said one of said slots, and one of said slots being of a greater width than the diameter of its stationary pin to permit movement of the end of said one of said arms adjacent said collar radially toward and from the periphery of said collar and said second stationary pin extending through a slot in said other of said arms which last slot extends generally perpendicular to the companion slot of said one of said arms.

7. A structure as set forth in claim 1 wherein said one of said arms has a central offset projecting generally parallel with said planes and providing with said other of said arms a continuous internal cam surface and wherein all of said salients form part of said cam surface.

References Cited in the file of this patent UNITED STATES PATENTS Thompson et al Apr. 29, 1941 

